Permittivity measurement of cementitious materials and constituents with an open-ended coaxial probe: combination of experimental data, numerical modelling and a capacitive model

RILEM Technical Letters

article

Vincent Guihard¹  Frédéric Taillade¹  Jean‐Paul Balayssac²  Barthélémy Steck¹  Julien Sanahuja¹ 

[1] EDF R&D;LMDC, INSA/UPS

关键词: Cementitious material;    Permitivity;    Co‐axial probe;    Capacitive model;    Numerical modelling;   

DOI  :  10.21809/rilemtechlett.2019.77

学科分类：社会科学、人文和艺术（综合）

来源: RILEM Publications SARL

【 摘 要 】

The study presents the development of a new two-dimensional FEM numerical model describing the operation of two large open-ended coaxial probes designed to investigate the permittivity of concrete, and its constituents. This numerical simulation, combined with a capacitive approach describing the behaviour of the probes, enabled to prove the suitability of such device to determine the permittivity of dispersive dielectrics. Finding back the permittivity of a specified material by calculation of the S parameters, change of the reference plane and use of the capacitive model is the key to the proof. Measurements performed onto different materials show good similarities with the numerical simulations. Special considerations are mentioned concerning the size of the probe and its ability to measure the permittivity of heterogeneous materials made of large inclusions. Combination of such numerical tool and measuring device can be used as a non-destructive testing technique to assess the near surface permittivity of concrete structures or as a calibration technique for GPR measurements.

【 授权许可】

CC BY